Air spring distance indicating system and method

ABSTRACT

A distance indicating system includes a transmitting portion, a transceiver spaced a distance from the transmitting portion, and a receiving portion supported in spaced relation to the transceiver. The transmitting portion broadcasting a first electromagnetic wave. The transceiver receiving the first electromagnetic wave and transmitting a second electromagnetic wave to the receiving portion. The transceiver is operative to modulate the second electromagnetic wave in relation to an input to communicate a signal, data or information, such as the distance between the transmitting portion and the transceiver, an acceleration input, a pressure level or a temperature reading.

BACKGROUND

The present novel concept broadly relates to the art of distancemeasurement and, more particularly, to a system and method forindicating the distance between associated structural members usingelectromagnetic wave modulation.

The subject system and method are amenable to broad use in a widevariety of applications and environments. One example of a suitableapplication is the use of the subject system and method on and with anassociated fluid suspension member, such as an air spring of a vehicle,for example. The subject system and method will be discussed in detailhereinafter with specific reference to use on such an associated fluidsuspension member. However, it is to be specifically understood that thesubject system and method are capable of broader application and are notintended to be limited to the specific examples shown and discussedherein, which are merely examples of suitable applications.

A variety of well known and commonly used devices and arrangements havebeen and are currently used to monitor the relative position of onestructural member to another. For example, mechanical linkage sensorsthat include one or more linkage members are often used to connectbetween adjacent structural members, such as a suspension component of avehicle and the corresponding frame or body of the same. The linkagemembers typically act through a variable resistor or other suitablecomponent that changes in response to the movement of the linkage. Anelectronic control unit (ECU) or other suitable device then determinesthe relative position of one structural member to the other based upon acorresponding change in voltage across the variable resistor or acorresponding change in current through the resistor.

Unfortunately, such arrangements have a number of problems and/ordisadvantages that are commonly associated with their continued use. Oneproblem with the use of mechanical linkages, particularly those used inassociation with the suspension system of a vehicle, is that thelinkages are frequently subjected to physical impacts, such as may becaused by debris from a roadway, for example. This can result in thelinkage being significantly damaged or broken, such that the device nolonger operates properly, if it operates at all.

Another problem with mechanical linkage sensors is that the electroniccomponents thereof are typically exposed to harsh environmentalconditions (e.g., temperature extremes, water, dirt, salt) normallyexperienced by a vehicle traveling along a roadway. As a result of suchexposure, the electronic components of the sensors can become corrodedand fail to function properly. Due to one or both of these or otherproblems, one or more of the mechanical linkage sensors may benon-operational at any given time. Thus, regular inspection andreplacement of such sensors is typically required.

Still another disadvantage of mechanical linkage sensors is that thesame are mounted separately from the other suspension components. As aresult, additional time and effort is typically spent installing thesecomponents during the assembly process. Furthermore, additional effortis typically involved in creating a clearance area for mounting andoperation of the mechanical linkage. Thus, such sensorsdisadvantageously require a significant amount of effort and space formounting and operation.

As an alternative to mechanical linkage sensors, non-contact sensorsthat utilize sound or pressure waves traveling through a fluid medium,typically at an ultrasonic frequency, have been used in determining therelative position of one structural member to another. One example ofsuch an application includes an ultrasonic sensor being used todetermine a height of a fluid suspension member, such as an air spring.In such a use, the ultrasonic sensor is supported on one end member ofthe air spring and sends ultrasonic waves through the spring chamber ofthe air spring toward the opposing end member. The waves are reflectedback by a suitable feature of the opposing end member and the distancetherebetween is determined in a conventional manner.

One advantage of such an arrangement over mechanical linkages is thatthe ultrasonic sensor is at least partially sheltered from impacts andexposure. However, numerous disadvantages also exist with the use ofultrasonic sensors. One such disadvantage is that such sensors arerelatively expensive which tends to undesirably increase productioncosts. Also, the replacement cost of a sensor that does get damaged byan impact or from exposure is likewise increased.

Another disadvantage is that ultrasonic sensors require a target that issuitable to reflect the ultrasonic waves back to the sensor fordetermining the distance therebetween. If such a target is not provided,the ultrasonic waves will not be reflected back properly and, thus, acorrect determination of distance will not be possible. Thus, a targetarea must be provided for the proper operation of ultrasonic sensors.This can be particularly problematic, however, where the designconstraints of a product limit the possibilities for including a targetarea. This is also a problem for existing products are being outfittedwith ultrasonic sensors, where the existing products do not have asuitable target area.

BRIEF DESCRIPTION

A distance indicating system in accordance with one embodiment of thepresent novel concept is provided that includes a transmitter forbroadcasting a first electromagnetic wave. A transceiver is supported ata distance from the transmitter. The transceiver is operative to receivethe first electromagnetic wave and to transmit a second electromagneticwave. The transceiver is also operative to modulate the secondelectromagnetic wave in relation to the distance. A receiver issupported in spaced relation to the transceiver and is operative toreceive the modulated second electromagnetic wave.

A distance indicating system in accordance with another embodiment ofthe present novel concept for an associated vehicle suspension systemthat includes an associated air spring assembly with first and secondend members and an elastomeric wall disposed therebetween is providedthat includes a transmitter supported adjacent the first end member forbroadcasting a first electromagnetic wave. A transceiver is supportedadjacent the second end member at a distance from the transmitter. Thetransceiver is operative to receive the first electromagnetic wave andto transmit a second electromagnetic wave. The transceiver is alsooperative to modulate the second electromagnetic wave in relation to thedistance. A receiver is supported in spaced relation to the transceiverand is operative to receive the modulated second electromagnetic wave.

An air spring assembly in accordance with one embodiment of the presentnovel concept is provided that includes a first end member, a second endmember spaced from the first end member and a flexible spring wallsupported between the first and second end members and at leastpartially forming a fluid chamber therebetween. A first transceiver issupported on the first end member and includes a first antenna fortransmitting a first electromagnetic wave and a second antenna forreceiving a second electromagnetic wave. A second transceiver issupported on the second end member at a distance from the firsttransceiver. The second transceiver includes a first antenna operativeto receive the first electromagnetic wave, a second antenna operative totransmit the second electromagnetic wave, and a processing device inelectrical communication between the first and second antennae. Theprocessing device receives an electrical signal having a relation to thedistance from the first antenna of the second transceiver. Theprocessing device also modulates a characteristic of the secondelectromagnetic wave in relation to the electrical signal.

A method of determining a distance between first and second end membersof an air spring in accordance with one embodiment of the present novelconcept is provided that includes providing a transmitter supportedadjacent the first end member and broadcasting a first electromagneticwave. The method also includes providing a transceiver supported inspaced relation to the transmitter adjacent the second end member andtransmitting a second electromagnetic wave. The method further includesinducing an electrical signal in the transceiver using the firstelectromagnetic wave, and modulating the second electromagnetic wave inrelation to a distance between the transmitter and the transceiver. Themethod also includes determining the distance between the transmitterand the transceiver based on the modulated second electromagnetic wave.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a representation of a distance indicating system in accordancewith the present novel concept shown in operative association with avehicle.

FIG. 2 is a side view, in partial cross section, of one exemplaryembodiment of an air spring assembly including a distance indicatingsystem in accordance with the present novel concept.

FIG. 3 is a schematic representation of one exemplary embodiment of adistance indicating system in accordance with the present novel concept.

FIG. 4 is a schematic representation of another exemplary embodiment ofa distance indicating system in accordance with the present novelconcept.

FIG. 5 is a schematic representation of one exemplary embodiment of atransceiver in accordance with the present novel concept.

FIG. 6 is a schematic representation of another exemplary embodiment ofa transceiver in accordance with the present novel concept.

DETAILED DESCRIPTION

Turning now to the drawings wherein the showings are for the purpose ofillustrating exemplary embodiments of the present novel concept and notfor limiting the same, FIG. 1 illustrates a vehicle 100 having a sprungmass, such as a vehicle body 102, for example, and an unsprung mass,such as axles 104 and wheels 106, for example. A plurality of dampingmembers, such as shock absorbers 108, for example, are secured betweenthe sprung and unsprung masses of the vehicle in a suitable manner.Additionally, a plurality of fluid spring members, such as air springassemblies 110, for example, are disposed between the sprung andunsprung masses of the vehicle adjacent wheels 106 and shock absorbers108.

Vehicle 100 also includes a fluid supply system 112 that is incommunication with air spring assemblies 110 and is operative toselectively supply and exhaust pressurized fluid therefrom. Fluid supplysystem 112 includes a pressurized fluid source, such as a compressor114, and can optionally include a storage vessel, such as reservoir 116,for example, for receiving and storing pressurized fluid from thepressurized fluid source. System 112 can further include a suitablefluid exhaust, such as a muffler 118, for example, for ventingpressurized fluid from the system.

Fluid supply system 112 can be in communication with the fluid springmembers in any suitable manner. For example, system 112 can include avalve assembly 120 or other suitable device or arrangement forselectively distributing pressurized fluid between the pressurized fluidsource or sources and the fluid spring members. As shown in theexemplary embodiment in FIG. 1, compressor 114, reservoir 116 andmuffler 118 are in fluid communication with valve assembly 120.Additionally, air spring assemblies 110 are in fluid communication withvalve assembly 120 via fluid lines 122. Thus, valve assembly 120 can beselectively actuated to transfer pressurized fluid from the compressorand/or reservoir to one or more of the air spring assemblies.Additionally, valve assembly 120 can be selectively actuated to exhaustpressurized fluid from one or more of the air spring assemblies by wayof muffler 118 or another suitable arrangement. It will be appreciatedthat the foregoing fluid supply system and operation thereof are merelyexemplary and that any other suitable fluid source, system and/or methodof operation can alternately be used.

Vehicle 100 also includes a suspension control system 124 forselectively operating one or more suspension system components, such asshock absorbers 108, air spring assemblies 110 and/or pressurized fluidsupply system 112, for example. Suspension control system 124 includesan electronic control unit 126 in communication with one or morecomponents of valve assembly 120, such as through a communication line128, for example, for selective actuation and/or operation thereof.Additionally, electronic control unit 126 is in communication with airspring assemblies 110 in a suitable manner, such as throughcommunication lines 130, for example.

Suspension control systems, such as control system 124, for example, areoperable in a wide variety of manners. For example, suspension controlsystems, such as control system 124, for example, can be used for heightadjustment (i.e., to selectively raise or lower the sprung mass of avehicle). As another example, suspension control systems, such ascontrol system 124, for example, can be used for leveling operations(i.e., to maintain the sprung mass of a vehicle in a substantially levelorientation). Given this common association with height monitoring andadjustment, suspension control systems typically utilize one or moreheight or distance sensors to monitor the vehicle height and/ororientation. A wide variety of height sensors and/or distancedetermining devices are known and commonly used, as discussed in one ofthe foregoing sections hereof. As an alternative arrangement, air springassemblies 110 include distance indicating systems in accordance withthe present novel concept that transmit electromagnetic waves 132 and134 to determine and communicate a height of the vehicle or distancebetween two vehicle or suspension system components.

One exemplary embodiment of a fluid suspension member in accordance withthe present novel concept is shown in FIG. 2 as air spring assembly 200that includes a first or upper end member 202, a second or lower endmember 204 and a flexible spring wall 206 secured therebetween. First orupper end member 202 is shown disposed along an associated upper vehiclecomponent UVC and second or lower end member 204 is shown disposed alongan associated lower vehicle component LVC. The upper and lower vehiclecomponents could, for example, be parts of or associated with therespective sprung and unsprung masses of the vehicle. Additionally, itwill be appreciated that the first and second end members can berespectively secured on the upper and lower vehicle components in anysuitable manner, such as by using fasteners (not shown), for example.Furthermore, it will be appreciated that air spring assembly 200 isshown in FIG. 2 of a rolling-lobe construction. It is to be understood,however, that this construction is merely exemplary and that any othersuitable construction can alternately be used.

Flexible spring wall 206 at least partially defines a spring chamber 208extending between end members 202 and 204. A suitable fluid line FLN,such as one of fluid lines 122 in FIG. 1, for example, is incommunication with spring chamber 208 through an opening formed throughone of the end members of the air spring assembly, such as passage 210formed through first end member 202, for example. A suitable connectoror fitting 212 can be used to maintain fluid line FLN in operativeassociation with spring chamber 208 through passage 210.

Air spring assembly 200 also includes a distance indicating system (notnumbered) that includes a first transceiver 214 and a second transceiver216 spaced a distance D1 from the first transceiver. First transceiver214 can be in communication with one or more devices or componentsthrough a conductive lead 218. For example, conductive lead 218 can berepresentative of communication line 130 in FIG. 1 extending between anair spring assembly 110 and electronic control unit 126. Additionally,electrical power can be supplied from an external power source (notshown), such as a battery or vehicle alternator, for example. As shownin FIG. 2, however, second transceiver 216 is preferably wireless. Thus,communication to and from second transceiver 216 occurs using a firstelectromagnetic wave EW1 and a second electromagnetic wave EW2.

In the exemplary embodiment shown in FIG. 2, first transceiver 214 issupported on first end member 202 and second transceiver 216 issupported on second end member 204. The first and second transceiverscan be secured on the end members in any suitable manner, such as byusing suitable fasteners, adhesives, bracketry or by manufacturing(e.g., molding) a transceiver or component thereof into or onto the endmember. Additionally, it is to be understood that such an arrangement ismerely exemplary and that any components of a distance indicating systemin accordance with the present novel concept can be mounting in otherpositions, orientations and/or arrangements.

It will be recognized from FIG. 2 that the first and second transceiverscan be used in a non-aligned orientation. That is, in the exemplaryembodiment shown in FIG. 2, second transceiver 216 is disposedapproximately centrally on the second end member whereas firsttransceiver 214 is disposed outwardly toward a peripheral edge of thefirst end member. As such, first transceiver 214 could optionallyinclude a second portion 214A that is separately mountable from thefirst portion and in communication with one or more other devices orcomponents through a conductive lead 218A. In such an arrangement, thefirst portion could be a transmitting portion and the second portioncould be a receiving portion. However, any other suitable configuration,arrangement or method of operation could alternately be used.

Furthermore, it will be appreciated that distance D2 between firsttransceiver 214 and first end member 202 and distance D3 between secondtransceiver 216 and second end member 204 will normally be fixeddistances. As such, one of skill in the art will recognize that thedistance between the transceivers, which is represented by dimension D1in FIG. 2, can also be representative of the height of air springassembly 200, as indicated by dimension D4, and that other dimensions ordistances could be similarly determined.

One exemplary embodiment of a distance indicating system 300 isschematically illustrated in FIG. 3 and includes a first transceiver 302and a second transceiver 304 spaced a distance D1 from first transceiver302. First transceiver 302 is in communication with a suitable externalpower source, such as a battery or an alternator of a vehicle, forexample, through a conductive lead 306. Additionally, first transceiver302 can be in communication with one or more other systems and/orcomponents 308, such as through a suitable conductive lead 310, forexample.

First transceiver 302 includes a transmitter 312 and a first antenna 314in communication with the transmitter. Suitably conditioned electricalpower can be provided to transmitter 312 from an external power source(not shown) through lead 306. Alternately, first transceiver 302 caninclude a power supply circuit 316 in communication with conductive lead306 for receiving electrical energy from a suitable electrical powersource. Circuit 316 can output conditioned electrical power ofappropriate voltages and/or current levels for use and operation ofother components of transceiver 302. For example, power supply circuit316 is shown in FIG. 3 in electrical communication with transmitter 312and provides conditioned electrical power thereto.

Transmitter 312 is operative to output a carrier wave signal that isbroadcast as a first electromagnetic wave EW1 using first antenna 314.Transceiver 302 also includes a receiver 318 in electrical communicationwith power supply circuit 316 and a second antenna 320 in electricalcommunication with receiver 318. Second transceiver 304 includes a firstantenna 322 operative to receive first electromagnetic wave EW1. Thesecond transceiver also includes a second antenna 324 operative totransmit a second electromagnetic wave EW2, which is received at secondantenna 320 of first transceiver 302 and communicated to receiver 318thereof. Second transceiver 304 can generate a modulation signalcorresponding to an input acting on an associated component of thedistance indicating system, such as a structural component upon whichthe second transceiver is supported, for example, and utilize themodulation signal to modulate a characteristic, such as frequency oramplitude, for example, of second electromagnetic wave EW2. The receiveris operative to recover a modulating signal from the secondelectromagnetic wave and generate an output signal related thereto toother devices and/or systems in a suitable manner, such as to componentor device 308 through conductive lead 310, for example.

Optionally, first transceiver 302 can include a processing device 326 incommunication with power supply circuit 316 that receives conditionedelectrical power therefrom. Additionally, processing device 326 is inelectrical communication with receiver 318 and can receive the outputsignal generated thereby. The processing device can then decode ortranslate the output signal into data and/or other information, such asdata related to a distance, acceleration value, temperature level,pressure level or other input, for example. The data and/or otherinformation can be communicated to other devices or systems, such as asystem or vehicle network 328 through a conductive lead 330, forexample.

In operation, first electromagnetic wave EW1 is transmitted from firsttransceiver 302 using first antenna 314 and is received by first antenna322 of second transceiver 304. In one exemplary embodiment, firstantenna 322 of second transceiver 304 includes an inductive element (notshown) or other suitable feature or component, and first electromagneticwave EW1 induces an electrical output across or along this inductiveelement to provide electrical power to second transceiver 304.Alternately, a separate electrical power source could be provided onsecond transceiver 304 to provide electrical power thereto, rather thanutilizing inductive coupling with first transceiver 302.

Those of skill in the art will recognize that one or more properties ofelectromagnetic waves vary with the distance of travel of theelectromagnetic wave, according to well-known relationships. Thus, byusing a suitable calculation, device or comparison, the distance oftravel of first electromagnetic wave EW1 (i.e., the distance D1 betweenthe first and second transceivers) can be determined by the secondtransceiver and communicated to the first transceiver or anothercomponent. Alternately, a signal corresponding to the distance of travelof first electromagnetic wave EW1 and/or other data or information canbe communicated from the second transceiver to a suitable device orcomponent for receiving wave EW1 and determining the distance and/orother data or information therefrom, such suitable components caninclude receiver 318 and/or processing device 326 of the firsttransceiver, for example.

Another exemplary embodiment of a distance indicating system 400 isshown in FIG. 4 and includes a transmitting portion 402, a receivingportion 404, and a transceiver 406. Transmitting portion 402 includes atransmitter 408 and an antenna 410 in communication with thetransmitter, which is operative to generate a carrier wave signal thatis broadcast as a first electromagnetic wave EW1 using antenna 410.Transmitter 408 can receive conditioned electrical power from anexternal power source through a suitable conductive lead, such as lead412, for example. Alternately, transmitting portion 402 can include apower supply circuit 414 that can receive electrical power from anexternal power source and output conditioned electrical power totransmitter 408.

Receiving portion 404 includes a receiver 416 and an antenna 418 inelectrical communication with receiver 416. Conditioned electrical powercan be provided from an external electrical power source through aconductive lead, such as lead 420, for example. Alternately, a powersupply circuit 422 can be included on receiving portion 404 that canreceive electrical power from an external power source and outputconditioned electrical power to the receiver. Receiver 416 is shown inFIG. 4 as being in electrical communication with a component or device424 through a conductive lead 426, and is operative to outputcommunication signals thereto. Optionally, a processing device 428 canbe included on receiving portion 404 that is in electrical communicationwith power supply circuit 422 and receiver 416. Processing device 428,if provided, can be operative to output data, signals and/or otherinformation to other components or systems, such as a vehicle or systemnetwork 430, for example, through a suitable connecting device, such asconductive lead 432, for example.

Transceiver 406 is shown in FIG. 4 as being spaced a distance D1 fromtransmitting portion 402. As such, first electromagnetic wave EW1travels across distance D1 and is received along a first antenna 434 oftransceiver 406. Transceiver 406 is operative to output a secondelectromagnetic wave EW2 from a second antenna 436 that is modulated tocommunicate signals, data and/or other information to receiving portion404, in a manner similar to that discussed above with regard to distanceindicating system 300. System 400 differs from distance indicatingsystem 300, however, in that receiving portion 404 can be positioned andsecured separately from transmitting portion 402. As such, receivingportion 404 is shown a being spaced a distance D5 from transceiver 406,which is shown as being of a greater magnitude than distance D1. It willbe appreciated, however, that distance D5 is merely representative of adistance that can be different from distance D1, and that a greater orlesser distance than that of distance D1 can be represented thereby.

One exemplary embodiment of a transceiver, such as transceivers 216, 304and 406, for example, which are respectively shown in and discussed withregard to FIGS. 2-4, is shown in FIG. 5 as transceiver 500, whichincludes a first antenna 502 and a second antenna 504. First antenna 502is operative to receive first electromagnetic wave EW1, and can includean inductive element (not shown) or other suitable device or component.First electromagnetic wave EW1 induces an electrical output across oralong this inductive element to provide electrical power to thetransceiver. Transceiver 500 also includes a power circuit 506 inelectrical communication with first antenna 502. Power circuit 506 canoperate to collect electrical energy induced on or along antenna 502 byfirst electromagnetic wave EW1. Alternately, a separate power source,such as a battery (not shown), for example, could be used.

A processing device 508 is in electrical communication with antenna 502and power circuit 506 through electrical conductors 510 and 512,respectively. Power circuit 506 outputs electrical energy to theprocessing device that is suitably condition for the operation thereof.Additionally, an electrical signal output from antenna 502 iscommunicated to processing device 508 along electrical conductor 510,and the processing device is operative to output a modulation signal toa transmitter 514 along an electrical conductor 516. In one exemplaryembodiment, the modulation signal output by the processing device has arelationship to the distance between the device or component that isbroadcasting the first electromagnetic wave (e.g., transceiver 302 ortransmitter portion 402) and transceiver 500. Power circuit 506 is alsoin communication with transmitter 514 through electrical conductor 518and supplies electrical power thereto. Transmitter 514 is operative togenerate a carrier wave signal and combine the carrier wave signal withthe modulation signal from processing device 508 to transmit secondelectromagnetic wave EW2 using second antenna 504.

According to one exemplary embodiment, processing device 508 can beoperative to translate or convert an electrical signal from antenna 502into an amplitude and/or frequency varied modulation signal in which thevariations in amplitude and/or frequency correspond to the voltage orcurrent level of the electrical signal from the antenna. Again, it willbe recognized that the voltage and/or current level of the electricalsignal from the antenna will vary with the distance of travel of thefirst electromagnetic wave, which corresponds to the distance betweenthe transceivers or other components. Thus, a distance measurement canbe communicated as variations in frequency and/or amplitude of anelectromagnetic wave. Therefore, electromagnetic wave EW2 is modulatedin relation to the distance between the first and second transceivers.The modulated electromagnetic wave can be received by a receiving deviceor component, such as first transceiver 302 or receiver portion 404, forexample, which can recover the modulation signal and output the same toa different component or system, which can determine the distance basedthereon. Alternately, the receiving device or component can convert themodulation signal or otherwise determine the distance based on themodulation of the second electromagnetic wave EW2 and output data and/orinformation corresponding to the distance.

One example of a suitable component for use as processing device 508 isa voltage controlled oscillator or voltage-to-frequency converter thatis operative to provide a variable frequency output in response tovariations in input voltage. One example of a suitablevoltage-to-frequency converter is available from National SemiconductorCorp. of Santa Clara, Calif. under the product designation LM231AN.

Another exemplary embodiment of a transceiver, such as transceivers 216,304, 406 and 500, for example, which are respectively shown in anddiscussed with regard to FIGS. 2-5, is shown in FIG. 6 as transceiver600, which includes a first antenna 602 and a second antenna 604.Transceiver 600 also includes a power circuit 606 in electricalcommunication with antenna 602 and is operable to collect electricalenergy induced on or along the first antenna as discussed above indetail. A processing device 608 is in electrical communication withpower circuit 606 through an electrical conductor 610 and receiveselectrical energy therefrom that is suitably conditioned for operationof the processing device. A first sensor 612 is in electricalcommunication between antenna 602 and processing device 608 throughelectrical conductors 614 and 616. In one exemplary embodiment, sensor612 is operative to output a signal related to the distance of travel offirst electromagnetic wave EW1, as discussed above, and to communicatethe sensor output signal to processing device 608.

Similar to processing device 508 in transceiver 500, first sensor 612can be operative to vary the frequency and/or amplitude of the outputsignal thereof in response to variations in the voltage and/or currentfrom antenna 602 along conductor 614. Alternately, an analog-to-digitalconverter or other suitable device can be used as sensor 612 to receivethe input from along conductor 614 and transmit a digitized outputsignal to processing device 608 along conductor 616. As such, processingdevice 608 includes a device, such as a programmable microprocessor,microcontroller or microcomputer, for example, that is capable ofreceiving the digitized sensor input signal and generating a modulationsignal corresponding to the distance of travel of the firstelectromagnetic wave.

The processing device, outputs the modulation signal to transmitter 618through an electrical conductor 620. Transmitter 618 is in electricalcommunication with power circuit 606 through electrical conductor 622.The transmitter generates a second carrier wave signal and combines thesame with the modulation signal to create modulated secondelectromagnetic wave EW2 that is transmitted by second antenna 604.

In one exemplary embodiment, transceiver 600 can also include one ormore additional components, such as sensors 614 and 616. It will beappreciated that components of any suitable number, type and/or kind canbe used, such as sensors operative to output sensor signals indicativeof an input acting on another portion or component, such as anacceleration, a fluid pressure, or a component or fluid temperature, forexample. As shown in FIG. 5, sensor 614 is in electrical communicationbetween power circuit 606 and processing device 608 through conductiveelements 628 and 630. Additionally, sensor 616 is in electricalcommunication between the power circuit and the processing devicethrough conductive elements 632 and 634. Examples of suitable sensorsinclude accelerometers, such as single and multi-axis accelerometers,for example; temperature sensors, such as thermocouples, for example;and pressure sensors, such as pressure transducers, for example.

If additional components, such as sensors 624 and/or 626, for example,are provided, processing device 608 will preferably be operative toreceive output signals from these components as well as from sensor 612.The processing device can then communicate the signals or data and/orinformation corresponding thereto to the receiving device or component.One example of suitable operation includes processing device 608combining or encoding the various output signals and generating amodulation signal suitable for communicating the data and/or informationfrom the sensors or other components. Optionally, signal encodingschemes can be used, such a frequency-shift keying, phase-shift keying,for example. Transmitter 612 then modulates the carrier wave using themodulation signal and the data and/or information is communicated to thefirst transceiver using second electromagnetic wave EW2, as discussedabove. The first transceiver or receiving portion can thereafter recoverand decode the modulation signal to output signals, data and/orinformation related to the output from the one or more sensors.

First electromagnetic wave EW1 and second electromagnetic wave EW2 arerespectively based upon first and second unmodulated carrier wavesignals. The unmodulated carrier wave signals can be generated in anysuitable manner and in one exemplary embodiment are generated by acorresponding transmitter. For example, the first carrier wave signalcan be generated by transmitter 312 or 408. Similarly, the secondcarrier wave signal can be generated by transmitter 514 or 618, forexample. It will be appreciated that any suitable properties and/orcharacteristics can be used for the carrier wave signals. For example,the carrier wave signals can have any suitable frequency, such as fromabout 20 kHz to about 30 GHz. In one exemplary embodiment, firstelectromagnetic wave EW1 is based upon a first carrier wave signalhaving a frequency within a range of from about 30 kHz to about 300 MHz.Additionally, such an exemplary embodiment includes a secondelectromagnetic wave EW2 based upon a second carrier wave signal havinga frequency within a range of from about 300 kHz to about 6 GHz. It isto be distinctly understood, however, that any suitable frequency orrange of frequencies can alternately be used.

While the subject novel concept has been described with reference to theforegoing embodiments and considerable emphasis has been placed hereinon the structures and structural interrelationships between thecomponent parts of the embodiments disclosed, it will be appreciatedthat other embodiments can be made and that many changes can be made inthe embodiments illustrated and described without departing from theprinciples of the subject novel concept. Obviously, modifications andalterations will occur to others upon reading and understanding thepreceding detailed description. Accordingly, it is to be distinctlyunderstood that the foregoing descriptive matter is to be interpretedmerely as illustrative of the present novel concept and not as alimitation. As such, it is intended that the subject novel concept beconstrued as including all such modifications and alterations insofar asthey come within the scope of the appended claims and any equivalentsthereof.

1. An air spring assembly comprising: a first end member; a second endmember spaced from said first end member; a flexible spring wallsupported between said first and second end members and at leastpartially forming a fluid chamber therebetween; a first transceiversupported on said first end member, said first transceiver including afirst antenna operative to transmit a first electromagnetic wave and asecond antenna operative to receive a second electromagnetic wave; and,a second transceiver supported on said second end member at a distancefrom said first transceiver, said second transceiver including a firstantenna operative to receive said first electromagnetic wave, a secondantenna operative to transmit said second electromagnetic wave, aprocessing device in electrical communication between said first andsecond antennae, said processing device receiving an electrical signalhaving a relation to said distance from said first antenna of saidsecond transceiver and modulating a characteristic of said secondelectromagnetic wave in relation to said electrical signal, and a sensorin electrical communication with said processing device, said sensoroperative to output a sensor signal to said processing device indicativeof an input acting on one of said second transceiver and said second endmember.
 2. An air spring assembly according to claim 1, wherein saidmodulated characteristic of said second electromagnetic wave is one ofamplitude and frequency.
 3. An air spring assembly according to claim 1,wherein said first transceiver includes a transmitting portion supportedon said first end member and a receiving portion supported adjacent saidfirst end member.
 4. An air spring assembly according to claim 1,wherein said first transceiver includes a transmitter in electricalcommunication with said first antenna thereof and said transmitteroperates at a frequency of from 30 kHz to about 300 MHz.
 5. An airspring assembly according to claim 1, wherein said first transceiverincludes a receiver in electrical communication with said second antennathereof and operative to generate an output signal having a relation tosaid distance.
 6. An air spring assembly according to claim 5, whereinsaid first transceiver includes a processing device in electricalcommunication with said receiver, said processing device receiving saidoutput signal and determining said distance based on said output signal.7. An air spring assembly according to claim 1, wherein said secondtransceiver includes a transmitter in electrical communication with saidsecond antenna thereof and said transmitter operates at a frequency offrom 300 kHz to 6 GHz.
 8. An air spring assembly according to claim 7,wherein said second transceiver is inductively coupled to said firsttransceiver, and said second transceiver includes a power circuit inelectrical communication with said first antenna thereof and operativeto collect electrical energy due to said inductive coupling with saidfirst transceiver.
 9. An air spring assembly according to claim 1,wherein said sensor is one of an accelerometer, a thermocouple and apressure transducer.
 10. An air spring assembly according to claim 1,wherein said processing device is operative to modulate a characteristicof said second electromagnetic wave in relation to said distance andsaid sensor signal.
 11. An air spring assembly according to claim 1,wherein said processing device includes one of a voltage-to-frequencyconverter, a microprocessor, a microcontroller or a microcomputer.
 12. Amethod of determining a distance between first and second end members ofan air spring, said method comprising: a) providing a transmittersupported adjacent the first end member and broadcasting a firstelectromagnetic wave; b) providing a transceiver supported in spacedrelation to said transmitter adjacent said second end member andtransmitting a second electromagnetic wave, wherein the transceiverincludes a sensor outputting a sensor signal related to an input level;c) inducing an electrical signal in said transceiver using said firstelectromagnetic wave; d) modulating said second electromagnetic wave inrelation to a distance between said transmitter and said transceiver andsaid sensor signal; and, e) determining said distance between saidtransmitter and said transceiver based on said modulated secondelectromagnetic wave.
 13. A method according to claim 12, wherein d)includes modulating said second electromagnetic wave using a modulatingsignal based upon one of amplitude modulation and frequency modulationto generate said modulated second electromagnetic wave.
 14. A methodaccording to claim 13, wherein modulating said second electromagneticwave includes generating said modulating signal based upon said inducedelectrical signal.
 15. A method according to claim 14 further comprisingproviding a receiver in spaced relation to said transceiver, saidreceiver receiving said modulated second electromagnetic wave andrecovering said modulating signal therefrom.
 16. A method according toclaim 12, wherein e) includes determining said distance and said inputlevel based on said modulated second electromagnetic wave.
 17. An airspring assembly comprising: a first end member; a second end memberspaced from said first end member; a flexible spring wall supportedbetween said first and second end members and at least partially forminga fluid chamber therebetween; a first transceiver supported on saidfirst end member, said first transceiver including a first antennaoperative to transmit a first electromagnetic wave and a second antennaoperative to receive a second electromagnetic wave; and a secondtransceiver supported on said second end member at a distance from saidfirst transceiver, said second transceiver including a first antennaoperative to receive said first electromagnetic wave, a second antennaoperative to transmit said second electromagnetic wave, a processingdevice in electrical communication between said first and secondantennae of said second transceiver, said processing device receiving anelectrical signal having a relation to said distance from said firstantenna of said second transceiver and modulating a characteristic ofsaid second electromagnetic wave in relation to said electrical signal,and an accelerometer in electrical communication with said processingdevice, said accelerometer operative to output a signal to saidprocessing device indicative of an input acting on one of said secondtransceiver and said second end member.
 18. The air spring assemblyaccording to claim 17, wherein said modulated characteristic of saidsecond electromagnetic wave is one of amplitude and frequency.
 19. Anair spring assembly according to claim 17, wherein said firsttransceiver includes a transmitting portion supported on said first endmember and a receiving portion supported adjacent said first end member.20. An air spring assembly according to claim 17, wherein said firsttransceiver includes a transmitter in electrical communication with saidfirst antenna thereof and said transmitter operates at a frequency offrom 30 kHz to 300 MHz.
 21. An air spring assembly according to claim17, wherein said first transceiver includes a receiver in electricalcommunication with said second antenna thereof and operative to generatean output signal having a relation to said distance.
 22. An air springassembly according to claim 21, wherein said first transceiver includesa processing device in electrical communication with said receiver, saidprocessing device receiving said output signal and determining saiddistance based on said output signal.
 23. An air spring assemblyaccording to claim 17, wherein said second transceiver includes atransmitter in electrical communication with said second antenna thereofand said transmitter operates at a frequency of from 300 kHz to 6 GHz.24. An air spring assembly according to claim 23, wherein said secondtransceiver is inductively coupled to said first transceiver, and saidsecond transceiver includes a power circuit in electrical communicationwith said first antenna thereof and operative to collect electricalenergy due to said inductive coupling with said first transceiver. 25.An air spring assembly according to claim 17, wherein said processingdevice is operative to modulate a characteristic of said electromagneticwave in relation to said distance and said accelerometer signal.
 26. Anair spring assembly according to claim 17, wherein said processingdevice includes one of a voltage-to-frequency converter, amicroprocessor, a microcontroller or a microcomputer.